1. Field of the invention
The present invention concerns a method and a device for rivetting a shroud to the blades of one stage of a rotor in order to bind them together, each blade comprising at its tip one or more tenons adapted to be inserted into one or more holes in the shroud, said tenons being at an acute angle c to the median plane of the rotor stage orthogonal to the axis of the rotor.
2. Description of the Prior Art
The patent U.S. Pat. No. 4 437 213 describes an automatic method of rivetting a shroud to a turbine rotor stage with radial tenons in which the rotor stage is moved in front of a rivetting head which is advanced and then retracted radially after each rivetting operation. This method is not usable if the tenons are at an angle to the plane of the rotor stage as the blades would be deformed by rivetting and the latter could not take place. This is why rivetting is currently carried out manually using a pneumatic gun or any equivalent impact device.
A method of this kind cannot produce consistently reproducible rivetting and its use is subject to specific constraints regarding legal provisions as to noise levels.